The short answer
8am in Tokyo is 5pm in Mountain Time on the previous day.
Tokyo is 15 hours ahead of Mountain Time. That's already evening in Mountain Time, after the typical working day ends.
Tokyo☀
8am
Mountain Time☀
5pm
previous day
Right now
9:57amJST · UTC+09:00 · Tue, Aug 25
6:57pmMDT · UTC-06:00 · Mon, Aug 24
Read across to convert
Tokyo
JST · UTC+09:00
Mountain Time
MDT · UTC-06:00
Pinned8amTokyo=5pmMountain Time · Mon (previous day)
12amTue
9amMon ·−1d
WORK1am
10amMon ·−1d
WORK2am
11amMon ·−1d
WORK3am
12pmMon ·−1d
WORK4am
1pmMon ·−1d
WORK5am
2pmMon ·−1d
WORK6am
3pmMon ·−1d
WORK7am
4pmMon ·−1d
WORKPINNED
8am
5pmMon ·−1d
NOW
9am
WORK6pmMon ·−1d
10am
WORK7pmMon ·−1d
11am
WORK8pmMon ·−1d
12pm
WORK9pmMon ·−1d
1pm
WORK10pmMon ·−1d
2pm
WORK11pmMon ·−1d
3pm
WORK12amTue
4pm
WORK1am
5pm
2am
6pm
3am
7pm
4am
8pm
5am
9pm
6am
10pm
7am
11pm
8am
daylightnightworking hoursoverlap
Best time to meet=
Closest workable window
Just outside the working window — early on one side, late on the other.
Tokyo
7am–10am
Mountain Time
4pm–7pm
previous day
Popular conversions
Quick reference.
9amTokyo=6pmMountain Time · prev day
12pmTokyo=9pmMountain Time · prev day
3pmTokyo=12amMountain Time
5pmTokyo=2amMountain Time
9pmTokyo=6amMountain Time
In context
What each side covers.
Mountain Time
6:57pmMDT · UTC-06:00
Cities on this clock
Related converters
Other popular pairs.
Pacific Time
5:57pm
India Standard Time
6:27am
Pacific Time to India12 hours 30 minutes behind
Eastern Daylight Time
8:57pm
Central European Time
2:57am
Eastern Time to Central Europe6 hours behind
India Standard Time
6:27am
Eastern Daylight Time
8:57pm
India to Eastern Time9 hours 30 minutes ahead
British Summer Time
1:57am
India Standard Time
6:27am
London to India4 hours 30 minutes behind
Pacific Daylight Time
5:57pm
Eastern Daylight Time
8:57pm
Pacific to Eastern Time3 hours behind
Central European Time
2:57am
India Standard Time
6:27am
Central Europe to India3 hours 30 minutes behind
Frequently asked
Quick answers about converting between Tokyo and Mountain Time. Can't find what you need? Email [email protected].
- What is the time difference between Tokyo and Mountain Time?
- Tokyo is 15 hours ahead of Mountain Time right now. We always show the live, daylight-saving-correct difference, so this figure already accounts for whichever side is observing summer time today.
- When it's 8am in Tokyo, what time is it in Mountain Time?
- 8am in Tokyo is 5pm in Mountain Time on the previous day. That's already evening in Mountain Time, after the typical working day ends. Use the hour-by-hour table above to read any other time across.
- What's the best time for a call between Tokyo and Mountain Time?
- There's no comfortable 9-to-5 overlap between Tokyo and Mountain Time — they sit on opposite sides of the planet's working day. Plan for an early or late call on one side, or hand work off asynchronously.
- Does this account for daylight saving time?
- Yes. We track every clock change in both places, so the abbreviations you see — JST and MDT — are the ones actually in effect right now, not a fixed all-year value. When either side changes its clocks, this page updates automatically.
- Why is the date sometimes different on each side?
- When two places are far enough apart, the same moment can fall on different calendar days. That is why some conversions are marked "previous day" or "next day" — it is the same instant in time, read off two clocks that crossed midnight at different points.